Electro-optic polymer

A polymer comprising (a) a base polymer having a reactive group (A), (b) an electro-optic molecule having a plurality of reactive groups (B), and a bond (C) formed by reaction of the reactive group (A) with the plurality of reactive groups (B), wherein the bond (C) is at least one type of bond selected from the group consisting of a (thio)ester bond, a (thio)urethane bond, a (thio)urea bond and a (thio)amide bond,

• wherein the (a) base polymer is a methacrylate-based base polymer,
• wherein the (b) electro-optic molecule comprises a compound represented by the following formula (1):
• wherein:
• RD1a, RD2a and RD3a independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryloxy group, an aralkyloxy group, a silyloxy group, an alkenyloxy group, an alkynyloxy group, a hydroxy group, —R1—OH (wherein R1 is a hydrocarbon group), —OR2—OH (wherein R2 is a hydrocarbon group), —OC(═O)R3 (wherein R3 is a hydrocarbon group), an amino group, —R4—NH2 (wherein R4 is a hydrocarbon group), a thiol group, —R5—SH (wherein R5 is a hydrocarbon group), —NCO or —R6—NCO (wherein R6 is a hydrocarbon group);
• RD4a and RD5a independently represent a hydrogen atom, an alkyl group, a haloalkyl group, an acyloxyalkyl group, a silyloxyalkyl group, —R1—OH (wherein R1 is a hydrocarbon group), —R4—NH2 (wherein R4 is a hydrocarbon group), an aryl group, —R5—SH (wherein R5 is a hydrocarbon group) or —R6—NCO (wherein R6 is a hydrocarbon group);
• X represents a linking group;
• and
• RA1a and RA2a independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an alkoxy group, a haloalkyl group, an aryl group, a hydroxy group, —R1—OH (wherein R1 is a hydrocarbon group), —OR2—OH (wherein R2 is a hydrocarbon group), an amino group, —R4—NH2 (wherein R4 is a hydrocarbon group), a thiol group, —R5—SH (wherein R5 is a hydrocarbon group), —NCO or —R6—NCO (wherein R6 is a hydrocarbon group),
• with the proviso that the compound has two or more reactive groups (B) selected from the group consisting of hydroxy, —R1—OH, —OR2—OH, amino, —R4—NH2, thiol, —R5—SH, —NCO and —R6—NCO contained in the formula (1), and
• wherein the polymer satisfies any one of the following (I) and (II):
• (I) RD1a is the reactive group (B) and at least one of RD4a, RD5a, RA1a and RA2a is the reactive group (B);
• and
• (II) RD4a and RD5a are the reactive groups (B).